LEIPZIG, GERMANY—Scientists have extracted and analyzed DNA from the 50,000-year-old toe bone of a Neanderthal woman found in Siberia's Denisova Cave in 2010 and put together a high-quality draft of the genome of modern human's closest extinct relative. The sequence allows for comparison between modern humans and other hominins, like Denisovans, another extinct hominin. For example, about two percent of the DNA of modern humans living in outside of Africa is from Neanderthals. The research also showed that Neanderthals and Denisovans interbred but not to the extent that there was a lot of genetic crossover—the Denisovan genome gets less than one percent of its genes from Neanderthals. Further, an unidentified human ancestor may have contributed up to six percent of the genes in the Denisovan genome. “This ancient population of hominins lived prior to the separation of Neanderthals, Denisovans and modern humans,” says Kay Prüfer, a researcher at the Max Planck Institute for Evolutionary Anthropology, Leipzig. “It is possible that this unknown hominin was what is known from the fossil record as Homo erectus.”